It remains to be seen whether this is actually the case.
It remains to be seen whether the European "fix" does anything whatsoever outside of the engine speed and load conditions seen in the NEDC. The way it was before, it only operated with emission controls if it followed the NEDC exactly. Probably now, they will remain operational if you drive generally within the speed and load conditions found in the NEDC but not necessarily following the cycle exactly - but at higher speeds and loads (the way most people actually drive) ... it remains to be seen what will happen.
I'm skeptical of the claim that it won't affect economy or performance. The way it was before, the emissions and economy were established via following the NEDC, during which the emission controls were active. Now, the emissions and economy will be established by following the NEDC, during which ... the emission controls are active just like before!
It remains to be seen what happens when the vehicle is driven under conditions outside of NEDC i.e. real world ... If the emissions are only reduced under the very light load conditions found in the NEDC, it's pretty likely that the economy and performance won't be affected much, but it's also pretty likely that the real-world emissions won't be affected much (i.e. they'll still be high - just as they have been finding with non-VW diesels in the EU - it will be the same situation)